Modular Refrigerator Shelf Frame to Reduce Warpage from Molded Stress
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Solution Overview
Problem
Existing variable-size refrigerator shelves face challenges with warpage due to molded-in residual stresses from differential shrinkage of plastic materials, leading to complex and costly manufacturing processes.
Innovation Solution
The U-shaped frame of the variable-size shelf is designed as a composable, modular structure composed of straight rear and side members, with precise locating features for easy assembly, reducing warpage and tooling costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a U-shaped frame is carefully designed to minimize warpage from molded-in residual stresses, then warpage is reduced, but manufacturing complexity and cost increase due to complex and expensive molds and manufacturing processes
Solution Approach 1:
The U-shaped frame is divided into multiple straight members (rear member, side members) that are assembled together using coupling means. This segmentation allows each member to be manufactured separately with simpler molds, avoiding the need for complex single-piece molds while minimizing warpage through the straight geometry of individual members.
2Ease of manufacture
If a single-piece U-shaped frame is used, then manufacturing process is simpler, but warpage occurs due to molded-in residual stresses from differential shrinkage
Solution Approach 1:
The frame is segmented into multiple straight members that are assembled together. This segmentation eliminates the differential shrinkage problem inherent in molded single-piece frames while maintaining ease of manufacture through standardized coupling mechanisms and straight member geometry that is simpler to mold than complex curved frames.
3Productivity
If a modular composable structure is used, then assembly time is reduced and manufacturing is simplified, but device complexity increases due to multiple components
Solution Approach 1:
The frame is divided into modular straight members with standardized coupling means, enabling quick assembly while keeping the number of components manageable. The segmentation allows for pre-manufactured precision components that assemble rapidly without requiring complex alignment procedures.
Solution Approach 2:
The coupling means is designed to be universal, allowing the same coupling mechanism to connect different straight members (rear member to side members, side members to each other). This universality reduces the variety of unique components needed while maintaining fast assembly capability.
Data Source
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AI summary
A refrigerator variable-size shelf (200) comprises a U-shaped frame (210) on which a first shelf portion (220) and a second shelf portion (230) are assembled. The first shelf portion (220) is hinged proximate a rear member (211) of the U-shaped frame (210), said rear member (211) being intended to be arranged at a back wall of a refrigerator compartment of a refrigerator appliance, and can be rotated between a horizontal position and a vertical position, while the second shelf portion (230) is slidably arranged on side members (212, 213) of the U-shaped frame (210) and can be moved from an extracted position, where it is substantially co-planar with the first shelf portion (220), and a retracted position, where it is received under the first shelf portion (220) and is coupled thereto by way of guides formed in its trim pieces (221, 222). The rear member (211) and the side members (212, 213) of the U-shaped frame (210) are manufactured as individual members and are assembled to one another by way of coupling means.